Change bgcolor on variable change.

[moondran]

Hi Guys/Girls

I’m using a while loop to get data from a database, The databsa consists of a tank_name and tank_reading fields. What I want to do is to make the bgcolor of each tank_name te same color. So in other words when the tank_name change then the bgcolor must change but all the tank_names that are the same must have the same bgcolor.

In example: this comes out of the db via while loop

 

Tank 1 bgcolor yellow

Tank 2 bgcolor red

Tank 3 bgcolor blue

Tank 2 bgcolor red

Tank 2 bgcolor red

Tank 1 bgcolor yellow

 

$sql1 = "select a.*, b.plant_nr AS plant_name, d.plant_nr AS tank_name 
from `table_tankReading` AS a 
LEFT JOIN `db_plant` AS b ON b.id=a.plant_id 
LEFT JOIN `db_plant_inc` AS c ON (c.plant_id=a.plant_id AND c.plant_category='Diesel Tank Type')
LEFT JOIN `db_plant` AS d ON d.id=tank 
WHERE 
(a.tank_reading_mine_id='$mine_id' AND a.tank_reading_month='$month_string' AND a.tank_reading_year='$year') 
ORDER BY a.tank+0, a.date_tank_reading
";
$result1 = $mysqli->query($sql1);
while($myrow1 = $result1->fetch_assoc()){
$tank_name = $myrow1["tank_name"];
echo"
<tr bgcolor="$bg"><td>$tank_name
</td></tr>";
}

 

Thanks for the help

 

[cyberRobot]

You could use a switch statement:

 

<?php
//...

echo "<tr bgcolor='";
switch($tank_name) {
case 'Tank 1': echo 'yellow'; break;
case 'Tank 2': echo 'red';    break;
case 'Tank 3': echo 'blue';   break;
}
echo "'><td>$tank_name</td></tr>";
?>

[moondran]

Thanks for the reply cyber. An switch might work yes, the only problem I have is that I don’t know what $tank_name value will be. So in short what I’m looking for is a method to test the value of $tank_name if it is the same as in one the pervious statement in the loop keep bg the same else change it to something new.

[PFMaBiSmAd]

<?php
$colors = array('yellow','red','blue','green'); // define enough colors for the number of different tank names

$fake[] = array('tank_name'=>'Tank 1'); // some fake data for demo purposes - actual data retrieved from database query
$fake[] = array('tank_name'=>'Tank 2');
$fake[] = array('tank_name'=>'Tank 3');
$fake[] = array('tank_name'=>'Tank 2');
$fake[] = array('tank_name'=>'Tank 2');
$fake[] = array('tank_name'=>'Tank 1');

$color = 0; // start at the first available color
$used = array(); // remember which colors have been used for each value
echo "<table>";
foreach($fake as $row){ // your while loop would replace this line
if(!isset($used[$row['tank_name']])){
	// no color exists for this tank name, assign it
	$used[$row['tank_name']] = $colors[$color++];
}
$bg = $used[$row['tank_name']]; // get the color assignment for the tank name
echo"<tr bgcolor='$bg'><td>{$row['tank_name']}</td></tr>";
}
echo "</table>";